ZA

Cognitive Neuroscience

Cognitive Neuroscience Overview

A summary of key concepts related to neural anatomy, communication, and early neuroscience developments.

Neural Anatomy

  • Key Components of Neuron:

    • Axon Hillock: Summation of stimuli leading to action potentials.

    • Terminal Button: Release of neurotransmitters into synapse.

    • Dendrite: Receives signals from other neurons.

    • Nucleus: Contains genetic material, regulates cellular activities.

    • Axon: Transmits action potentials away from the cell body.

    • Myelin Sheath: Insulates axons, speeding up signal transmission.

    • Cell Body/Soma: Contains the nucleus and organelles of the neuron.

    • Node of Ranvier: Gaps in the myelin sheath for saltatory conduction.

    • Synapse: Junction between neurons where communication occurs.

Neural Communication

  • Propagation of Signals:

    • Action Potentials: Rapid depolarization of neuron membrane leading to nerve impulses.

    • Neurotransmitters: Chemicals transmitting signals across synapse.

    • Excitatory Postsynaptic Potential (EPSP): Increases likelihood of action potential.

    • Inhibitory Postsynaptic Potential (IPSP): Decreases likelihood of action potential.

    • Long Term Potentiation (LTP): Persistent strengthening of synapses due to repeated stimulation (Hebbian Learning).

Historical Perspectives in Neuroscience

  • Ancient Greek & Roman Ideas:

    • Brain as a cooling mechanism for heart; 'sensus communis' concept.

  • Middle Ages:

    • Ideas of three ventricles in brain (Imagination, Memory, Reason).

    • Ibn Sina's analogy for brain function regarding senses.

  • Early Renaissance:

    • Emphasis on dissections and anatomical studies (Leonardo Da Vinci, Galen).

  • Late Renaissance:

    • Framework for brain terminology (Cerebellum, Cerebrum).

    • Thomas Willis' studies laid foundations for cerebral circulation knowledge.

Localization of Function vs. Mass Action

  • Case Studies:

    • Phineas Gage as an example of brain damage impacting personality

    • Broca’s area: left hemisphere correlates with language production (motor aphasia).

    • Wernicke’s area: comprehension deficits associated with fluent but nonsensical speech.

Memory Processing

  • Brain Structures Supporting Memory:

    • Hippocampus: Critical for consolidation of new memories.

    • Amygdala: Emotion-associated processing and memory.

  • Types of Memory:

    • Episodic Memory: Personal recollections of events.

    • Semantic Memory: Facts and concepts, independent of context.

    • Skill Memory: Memory of skills that may remain intact in amnesiacs (e.g., Clive Wearing’s piano playing).

End of Section Summary**

  • Understanding innermost workings of the brain can provide insights into behaviors and cognitive functions.

    • Emphasis on the structure-function relationship essential for cognitive neuroscience.